


Practice Makes Perfect

by ithilien22



Series: Practice Makes Perfect 'Verse [1]
Category: Shadowhunters (TV)
Genre: M/M, Sex Talk, Sibling Bonding
Language: English
Status: Completed
Published: 2016-06-19
Updated: 2016-06-19
Packaged: 2018-07-15 21:52:37
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,255
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7239907
Author URL: https://archiveofourown.org/users/ithilien22/pseuds/ithilien22
Summary: <blockquote class="userstuff">
              <p>To be fair, Isabelle had told Alec to come to her when he wanted to talk.</p>
            </blockquote>





	Practice Makes Perfect

**Author's Note:**

> Everyone seems to like the 'Alec has awkward discussions with Jace about sex' bits I've done in a couple of my fics, so now it's Izzy's turn! I actually tried to parallel the Alec & Jace scene in '[Show Me Off](http://archiveofourown.org/works/7070869)' a bit, but idk how successful I was. 
> 
> The premise for Izzy & Alec's conversation is based on a throwaway line in '[Let's Put That Mouth To Good Use](http://archiveofourown.org/works/6983158)' and a subsequent tumblr prompt (thanks stirfryedshana & sohavelocksaid)!

Alec's stomach is in a knot. He's been pacing outside of his sister's door for nearly twenty minutes now, but he can't seem to make himself open it. Several times he's actually given up and decided to leave, but he never quite makes it to the end of the hallway before shaking his head and forcing himself to come back. She's the only person he can ask, and he knows she won't make fun of him. _Well, at least not much_ , he thinks.

He hopes.

One thing is certain, though; he can't keep doing this all day. He's on patrol in less than an hour, so if he's going to do something, it needs to be now. He takes a deep, steadying breath, and finally knocks a few sharp taps on the heavy door. Then, after waiting another few moments, he lets himself inside.

Isabelle is lying on her stomach on her bed, engrossed in a rather daunting looking anatomy book. She smiles when she sees Alec, immediately closing the book and sitting up.

"Mission?" she asks, already swinging her feet off the edge of the bed in excitement.

"Uh no, sorry," Alec responds, twisting his hands together nervously. Isabelle sinks back down onto the bed, eyebrows raised slightly in curiosity or confusion, Alec's not sure. "I just wanted to- I, um. Could we talk?"

Now Isabelle looks worried. She shifts over a bit to make room for Alec to sit next to her. He hesitates, but after a moment he joins her on the bed.

"What's wrong?" Isabelle asks him, voice gentle. Alec can feel the heat rising to his cheeks already. By the angel, it's so embarrassing.

"Nothing's wrong," he tries to assure her, but his voice comes out a bit shaky. He clears his throat.

"I just, um." He stops, starts again- "I wanted to talk to you. But it's kind of, uh. Personal."

Isabelle's eyes light up, but Alec can tell she's making an effort to keep too much excitement from showing on her face. He's suddenly reminded of a conversation they had a few month's ago, where Isabelle had accused him of never talking to her about his personal life.

He also remembers her offer, and he knows it was sincere, but even so, he sort of doubts she meant for him to talk to her about _this._

Despite the glint in her eye, Isabelle's tone is suspiciously neutral when she speaks again.

"Oh?" she asks, casually. "Did something happen with Magnus?"

Alec fidgets with his hands some more, staring blindly at his and Isabelle's reflection in her vanity on the opposite wall. He's stalling again, and he knows it. He just can't seem to make himself look over at Isabelle directly, though. He can't talk about this and look her in the eye at the same time.

To be honest, he's not sure if he'll ever be able to look her in the eye again after this.

"Its, uh. I actually have a... _sex_ question," he finally admits, practically whispering even though they're the only two people in the room. Isabelle doesn't even try to hide her grin at his admission. She's practically beaming in the mirror's reflection.

"I knew it finally happened," she teases, "you've been smiling so much lately."

Alec rolls his eyes. "Iz-"

"Okay, okay," she relents at the pleading in his voice, but she's still grinning. "Just tell me. Or ask me, whatever. I won't laugh, I promise."

Alec grimaces. He doesn't find that statement to be particularly comforting. But, on the other hand, he's made it this far. So-

"How do you give a blowjob?" he blurts, voice low and words rushing together, "I mean, obviously I know how to, uh- but, I mean. Without um- without, you know..."

He trails off into a vague gesture, his face burning.

"You gagged a little, huh?" she guesses, tone sympathetic. Unlike Alec, she seems completely unembarrassed by the topic at hand. "Don't worry, that just happens sometimes at first. I'm sure Magnus didn't think it was a big deal."

"Some guys even think it's a compliment," she adds, rolling her eyes a bit. "You know- they're so big or so overwhelming or whatever."

"What- no! I. No." Alec shakes his head. He doesn't know what he expected, but he's already regretting not turning around at Isabelle's door when he had the chance. "I didn't- I haven't..."

"Oh," Isabelle says, cutting off his stuttering as she catches on. "I get it - you haven't actually tried yet. You're too nervous."

Alec just nods tightly.

"Well, I don't think there's a right way, exactly. It just takes practice, you know? If you're worried about choking, just don't try to take it all at once," she suggests. "Go slow, and just use your hands where your mouth doesn't reach."

Alec groans, making a face as he listens to Isabelle's advice. Her _sex_ advice. His little sister's sex advice.

"But you know, you can get over your gag reflex if you really want to," she tells him, seemingly oblivious to his inner turmoil. "You wanna know how I learned?"

"No," he responds quickly, because he doesn't want to think about that at all, actually. _By the angel._

"A cucumber," she says, ignoring him.

He so surprised he actually looks over at her in his confusion.

"What?"

"Yeah, you know, for practice," she says. "We can go get one from the kitchen and I'll show you-"

"By the angel, Izzy!" Alec says, standing from the bed and glaring down at her.

She's laughing outright now, the corners of her eyes actually starting to tear up as she watches him splutter in indignation.

"Just kidding, big brother," she laughs. Then after a beat, she adds, "just about the demonstration, not about practicing. And if you really do need a demonstration, you could always download some porn."

"You're a terrible sister," he informs her. He feels like his whole body must be bright red at this point. He's definitely done with this conversation now, and he's going to be late for patrol soon anyway. "I'm never talking to you about anything ever again."

"I'll send you some links!" she calls at his retreating back and he rolls his eyes even though she can't see him.

"Please don't," he says, but he doesn't stop walking to look back at her, so he can't be sure she even hears him.

Once he's outside her room, he leans his head against the door for a few seconds and tries to will the flush off of his cheeks. Eventually, he feels under control enough to head back out to the floor and prepare for patrol, which thankfully turns out to be eventful enough that he has much more important things occupying his mind for the rest of the night.

It's not until he gets back to his room at the institute, hours later, that his conversation with Isabelle comes back to him. He's that perfect combination of amped and exhausted, the way he always is after a good fight, and all he wants to do is take a hot shower and then sleep for the next half-day at least. He's so intent on this plan, in fact, that when he enters his room he almost doesn't notice it. He's halfway to his en suite bathroom before he catches it out of the corner of his eye, and he slowly turns around, stomach dropping in dread.

Sitting on his bed, wrapped in a bright red bow, is a cucumber.

**Author's Note:**

> Come prompt me on [tumblr](https://ithilien-writes.tumblr.com/)!


End file.
